Apparatus for absorbing or damping vibrations of the ground

ABSTRACT

An apparatus for absorbing or damping vibrations of the ground caused by an earthquake or other causes before being transmitted to a building. The apparatus broadly comprises a main vibration absorbing assembly and an auxiliary load carrying assembly both of which are separately interposed between a groundsill of the building and a foundation thereof and used in juxtaposed relation. The main vibration absorbing assembly comprises a plurality of main springs arranged between the groundsill of the building and the foundation with the axes thereof being inclined upwardly and inwardly so as to converge in a vertical line. The auxiliary load carrying assembly comprises a frame mounted under the groundsill in a position directly under a strut of the building, and a ball supported at the lower end of the frame in rolling engagement with the foundation.

United States Patent 1191 Nakayama [451 Sept. 23, 1975 Tadayoshi Nakayama, 2-24-10 Sekimae, Musashino, Tokyo, Japan 22 Filed: Dec. 13,1973

21 Appl.No.:424,2l4

[76] Inventor:

[30] Foreign Application Priority Data 675,982 12/1963 Canada 52/167 Primary ExaminerErnest R. Purser Assistant ExaminerHenry Raduazo Attorney, Agent, or Firm-Kane, Dalsimer, Kane, Sullivan and Kurucz [57] ABSTRACT An apparatus for absorbing or damping vibrations of the ground caused by an earthquake or other causes before being transmitted to a building. The apparatus broadly comprises a main vibration absorbing assembly and an auxiliary load carrying assembly both of which are separately interposed between a groundsill of the building and a foundation thereof and used in juxtaposed relation. The main vibration absorbing assembly comprises a plurality of main springs arranged between the groundsill of the building and the foundation with the axes thereof being inclined upwardly and inwardly so as to converge in a vertical line. The auxiliary load carrying assembly comprises a frame mounted under the groundsill in a position directly under a strut of the building, and a ball supported at the lower end of the frame in rolling engagement with the foundation.

2 Claims, 8 Drawing Figures US Patent Sept. 23,1975 Sheet 1 of 2 3,906,689

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US Patent Sept. 23,1975 Sheet 2 of2 3,906,689

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. 1 I APPARATUS FOR ABSORBING OR DAMFING VIBRATIONS OF THE GROUND BACKGROUND OF THE INVENTION This invention relates to an apparatus for absorbing or damping any vibrations of the ground due to an earthquake or other causes before being transmitted to a building to prevent the building from being destroyed or collapsed.

Heretofore, buildings such as houses and the like, particularly wooden houses have been fixed directly on the foundations by suitable clamping means such as foundation bolts, and hence vibrations due to an earth quake or other causes were transmitted from the ground through the foundation to such buildings. As a result, some bitter experiences of the past show that when great earthquakes occured, a number of buildings were frequently destroyed or collapsed, causingmany serious casualties.

BRIEF SUMMARY OF THE INVENTION Accordingly, it is an object of the invention to provide a novel apparatus for absorbing or damping any vibrations of the ground before being transmitted to a building.

It is another object of the invention to provide an apparatus for absorbing or damping any vibrations of the ground, which is of small size, simple in construction and inexpensive to manufacture.

It is a further object of the invention to provide a means for carrying the load of a building in rolling engagement with the foundation.

It is still a further object of the invention to provide a means for absorbing or damping vibrations of the ground which can be used in combination with the load carrying means.

According to the invention, there is provided an apparatus for absorbing or damping any vibrations of the ground before being transmitted to a building, comprising a main vibration absorbing or damping means including a plurality of first resilient means arranged between the groundsill of the building and the foundation with the axes thereof being inclined upwardly and inwardly so as to converge in a vertical line, said first resilient means each being pivotally connected one end to the groundsill and at the other end to the foundation for tilting movement in every direction, and an auxil iary load carrying means firmly mounted under the groundsill of the building in rolling engagementwith the foundation, said auxiliary means being used in juxtaposed relations with said main means: Y

The above and other objects and features of the invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference numerals designate corresponding parts in the several views.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view, partly in section of a main vibration absorbing means constituting a part of an appartus according to the invention.

FIG. 2 is a top plan view of the main vibration absorbing means illustrated in FIG. 1.

FIG. 3 is an elevational view explaining the operation of the main vibration absorbing means according to the invention.

FIG. 4 is a perspective view of the main vibration absorbing means interposed between the groundsill of a building and the foundation.

FIG. 5 is an elevational view of an auxiliary load carrying means constituting a part of the apparatus according to the invention.

FIG. 6 is a side view of the auxiliary load carrying means shown in FIG. 5.

FIG. 7 is a bottom plan view of the auxiliary load carrying means.

FIG. 8 is a perspective view of the auxiliary means interposed between the groundsill of a building and the foundation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, the embodiment of an apparatus for absorbing or damping vibrations of the ground according to the invention broadly comprises a main vibration absorbing means which is generally designated as reference numeral 10 in FIGS. 1-4 and an auxiliary load carrying means which is generally designated as reference numeral 40 in FIGS. 5-8.

Referring first to FIGS. 1-4, the main vibration absorbing means will be explained below. A square base plate 12 is provided at its middle portion with two holes 14 to mount it fixedly on a foundation 60 as shown in FIG. 4 and at its four corners with four holes 16 for rods 18 which are preferably rounded along the upper and lower peripheral edges so that the rods 18 may be freely tilted in every direction. Secured to the under surface of the base plate 12 around each hole 16 is a casing 20 for receiving a head 22 of the rod 18. This head 22'may be integrally formed with the rod 18 or separately in the form of nut to threadably engage with the rod 18.

On the other hand, a frame 24, which is to be mounted under a groundsill of a building, is preferably of channel shape so that the groundsill 70 may be interposed within the channel of the frame 24 and firmly secured therein with suitable clamping means such as bolts vertical walls 24b of the frame 24. The frame 24 is provided at the middle of the bottom 24a with four holes 28 each being positioned in corresponding relation to each of four holes 16 on the base plate 12, respectively. The holes 28 are preferably rounded along the upper andlower peripheral edges in the same way as in the base plate 12.

' Each of the rods 18 extends upwardly in tilted position from the casing 20 through the respective holes 16 of the base plate 12 and the respective holes 28 of the frame 24 to the interior of the frame 24. Each rod 18 is formed at the top end with a thread 30 and a frusto conical nut 32 having a corresponding internal thread therein is threadably engaged with the rod 18.

Each of four helical springs 34 is mounted on each rod 18 between the base plate 12 and the frame 24 will bell type washers 36 being interposed at both ends of the springs 34. In this way, the helical springs 34 extend around the rods 18 in inclined positions from the four corners of the base plate 12 towards the middle portion of the frame 24, so that when the frame 24 and consequently the rods 18 have been moved relative to the base plate 12 as shown in FIG. 3 with vibrations of the the frame 24 moved by vibrations of the ground to its original position. FIG. 4 illustrates the main vibration absorbing means 10 interposed between the groundsill 70 of a building and the foundation 60. It goes without saying that in mounting the main vibration absorbing meansblO, the groundsill 70 should be formed with a recess 39 for receiving the top portions of rods 18 and the conical springs 38 for movement therein as shown in FIG. 2..

Referring now to FIGS. -8, there is shown an auxiliary load carrying means 40 which is used in combination with the aforementioned main vibration absorbing means 10.

The load carrying means 40 comprises a frame 42 which is to be mounted under the groundsill 70 of the building The frame 42 includes a base plate 420 and L-shaped vertical walls 42b, 42c extending oppositely and upwardly from the periphery of the base plate 421:. The corner of the groundsill 70 on which a strut 71 is positioned may be interposed between the vertical walls 42b and 426 of the frame 42 and clamped with clamping means such as bolts and nutsv Four legs 44 extend downwardly from the middle portion of the base 42:: of the frame 42 in crossed relation at right angles to one'another and each of opposed legs 44 defines at its lower end a circular are 46 which is adapted to correspond to the curvature of a ball 48 and serves to carry rotatably the ball therein. The angle of the circular are 46 is preferably more than 180 to prevent the ball 48 from releasing therefrom.

Preferably, in mounting of the auxiliary load carrying means 40, a rigid plate 50 of steel or the like having a smooth rolling surface may be firmly mounted on the foundation 60 to reduce the rolling friction of the ball. The rigid plate 50 may be grounded for minimum rolling friction and plated against corrosion.

In this'embodiment of the invention, the frame 42 is forme'd'w'ith' opposed vertical walls, but is may be composed of only a base plate 42a.

In mounting the apparatus according to the invention, a number of the main vibration absorbing means are mounted in any required places between the groundsill 70 of a building and the foundation 60 as shown in FIG. 4, while the auxiliary load carrying means 40 are mounted between the groundsill 70 and the foundation 60 preferably in positions directly under the struts 71 as shown in FIG. 8 and if required, in any other places.

With the above described apparatus so mounted, should an earthquake happen, the main vibration absorbing means 10 absorb or damper the vibrations transmitted from the ground, by means of a plurality of helical springs arranged in inclined positions, while the vibration of the ground also causes the auxiliary load carrying means 40 to be rolled freely on the foundation, absorbing the horizontal acceleration of the vibration, so that the rods 18 or helical springs 34 of the main vibration absorbing means may be freely tilted for damping of the vibration, thus the building being only subjected to minimized acceleration of vibration. Upon a ceasing of the earthquake, the helical springs 34 together with the conical springs 38 forces the frame 24 or the rods 18 to restore to their original positions and consequently the building may be restored to its original position.

In this way, the apparatus according to the invention permits the buildings to be protected completely from destruction or collapse by the combined damping or absorbing action of the main vibration absorbing means and the auxililary load carrying means, and hence human life can be safely protected.

The experiments associated with the invention proved that the apparatus according to the invention provided a capacity sufficicnt to absorb or damper an earthquake of magnitude 7.58 and horizontal vibration 0.3-0.4, and also provided a sufficicnt resisting force to a typhoon.

What is claimed is:

1. An apparatus for absorbing a damping vibration of the ground before being transmitted to a building, comprising a main vibration damping means including a plurality of rods which are each at a lower end pivotally connected to a base secured to a foundation and at an upper end loosely fitted through a frame secured to a groundsill so as to be tilted independently of one another said rods being inclined upwardly and inwardly toward each other so as to converge in a vertical line, a plurality of first resilient means arranged about said rods between the base and the frame to damp mainly vertical and horizontal vibrations, and a plurality of second resilient means arranged about said rods between the frame and the upper ends of the rods to restore the rods to the respective initial inclined positions; and an auxiliary load carrying means including a frame having legs extending downwardly secured to the groundsill, and a ball supported at the lower end of the legs in rolling engagement with the foundation, said auxiliary load carrying means being arranged in juxtaposed relation with respect to said main vibration absorbing means.

2. An apparatus as set forth in claim 1 wherein said second resilient means consist of a plurality of conical springs. 

1. An apparatus for absorbing a damping vibration of the ground before being transmitted to a building, comprising a main vibration damping means including a plurality of rods which are each at a lower end pivotally connected to a base secured to a foundation and at an upper end loosely fitted through a frame secured to a groundsill so as to be tilted independently of one another said rods being inclined upwardly and inwardly toward each other so as to converge in a vertical line, a plurality of first resilient means arranged about said rods between the base and the frame to damp mainly vertical and horizontal vibrations, and a plurality of second resilient means arranged about said rods between the frame and the upper ends of the rods to restore the rods to the respective initial inclined positions; and an auxiliary load carrying means including a frame having legs extending downwardly secured to the groundsill, and a ball supported at the lower end of the legs in rolling engagement with the foundation, said auxiliary load carrying means being arranged in juxtaposed relation with respect to said main vibration absorbing means.
 2. An apparatus as set forth in claim 1 wherein said second resilient means consist of a plurality of conical springs. 